A system-on-a-chip (SoC) integrates different technologies, such as digital circuits, analog circuits, mixed-signal circuits, memory circuits, etc., into a single semiconductor chip. A SoC is typically used in embedded applications to reduce the space and power requirements of the system and to reduce the assembly costs of the system compared to using multiple semiconductor chips to achieve the same function as the SoC. SoCs are typically expensive to fabricate due to the multiple technologies (e.g., analog, digital, etc.) included on a single semiconductor chip and due to the typically lower yields achieved when multiple technologies are combined on a single semiconductor chip.
An alternative to SoCs is two or more stacked semiconductor chips, which can provide similar functions as a SoC in a small package. Each semiconductor chip within the stack of semiconductor chips may include a single technology, thereby reducing the cost of each semiconductor chip and typically increasing the yields. To interconnect the semiconductor chips within a stack of semiconductor chips, however, specialized tools and/or expensive processes are typically used.
For these and other reasons, there is a need for the present invention.